trashtray
An ashtray in a common area where nonsmokers place their gum, pieces of paper, take-out coffee cups and other non-cigarette trash.
Dude, watch where you put out your cig. With all this paper in the trashtray you might actually set something on fire.
Trashtray
An ashtray that gets used for trash and garbage along with cigarette butts and ashes - sometimes resulting in smoldering/stinky smoke or fire.
The trashtray is overflowing and needs to be emptied.